To: Edgar I. Castro

From: Jon Hagen

Date: 11-13-98

Subject: Monthly Report for October, 1998

Andy Dowd and I "reverse engineered" the unreliable regeneration board used in the Vertex system. Several components were replaced with components of higher ratings. Andy is designing a replacement board.

A maintenance manual is being prepared for the Drive System. This in-house document will contain an engineering overview of the system, detailed operating instructions, and a concordance to the documentation supplied by Vertex.

The electronics for the overspeed limiter were packaged in a waterproof enclosure. The tachometer unit was fitted with the spring bar that keeps its pinion engaged with the elevation rack gear. This system will be installed on one of the Gregorian drive trucks in November. The Ithaca lab is producing a second unit to be fitted to the carriage house.